FKBP4 and major depressive disorder: The larger homolog FKBP51[2] is a regulator of glucocorticoid receptor (GR) signaling[3] and has emerged as a potential target for depression,[4] obesity‐induced diabetes[5] and chronic pain.[6] In contrast, the homologous proteins FKBP12, FKBP12.6 and FKBP52 are considered anti‐targets due to their important roles in cardiology, sexual development and female infertility, emphasizing the need for selective inhibition.[7]